Unmarked police cars arrived at Royal Lodge this morning for the fourth day in a row as they continue to gather evidence following the arrest of Andrew Mountbatten-Windsor.
The former prince, 66, was arrested on Thursday morning on suspicion of misconduct in a public office, and spent 11 hours in police custody before being released pending further investigation.
Police are expected to continue their search of Royal Lodge in Windsor Great Park until Monday.
Andrew lived on the estate from 2004 until he was kicked out at the beginning of the month, reportedly paying 'peppercorn rent' for years.
Four police patrol cars were also seen arriving at Andrew's current home at Wood Farm on the Sandringham Estate.
It comes as former security minister Tom Tugendhat called for Parliament to launch a treason investigation into Andrew and Lord Mandelson surrounding their links to Jeffrey Epstein.
Mr Tugendhat said a special committee of MPs, peers and retired judges should look into the implications for the state.
He said the issues go 'beyond what a court could reasonably consider' - suggesting the inquiry should be able to summon witnesses and demand evidence.
Andrew Mountbatten-Windsor was pictured looking shell-shocked after spending a day in police custody on Thursday
Unmarked police cars were seen arriving at Andrew's former home, Royal Lodge in Windsor today
Police patrol cars were seen arriving at Wood Farm this morning, the property where Andrew currently resides
The former prince and Lord Mandelson are being investigated by police over allegations of misconduct in public office. Both deny any criminal wrongdoing.
Accusations over Andrew's links to Epstein have plagued the family for years and finally came to a head with the release of files from his estate by the US Department of Justice.
Some appeared to show the eighth-in-line to the throne sharing sensitive information during his time as a trade envoy.
Mr Tugendhat, a Tory MP, told the Sun on Sunday: 'This affair raises urgent questions about foreign influence and national security. What did the Palace know? What did ministers know? What else is being hidden?
'This goes beyond what a court could reasonably consider. Parliament must consider what it means for the country. If the worst is proved, do we need to revisit treason laws written 700 years ago?'
He added: 'If these accusations are true, they expose something rotten at the top of the State. If they are not, the public needs proof that the guardrails are strong.
'Either way, Parliament must send a clear message - Britain will defend itself from every threat, even if it comes from the very top.'
Former security minister Tom Tugendhat called for Parliament to launch a treason investigation into Andrew
Four police patrol cars were seen arriving at the Sandringham Estate to keep it secure following his arrest
Andrew is now residing at Wood Farm on the King's private estate, the property where his father spent much of his final years.
The home is hidden from public view, around 300 yards down a private driveway in Wolferton on the edge of the Norfolk estate.
He is eventually set to move into his new home in Marsh Farm, a far less private property on the estate, which is still undergoing renovations to make it ready for his arrival.
The arrest of the former prince triggered arguably the biggest crisis in the monarchy for nearly 400 years.
In an unprecedented personal statement on Thursday, King Charles expressed his 'deepest concern' that the police had picked up his brother on his 66th birthday.
Charles said: 'I have learned with the deepest concern the news about Andrew Mountbatten-Windsor and suspicion of misconduct in public office.
'What now follows is the full, fair and proper process by which this issue is investigated in the appropriate manner and by the appropriate authorities. In this, as I have said before, they have our full and wholehearted support and co-operation.
'Let me state clearly: the law must take its course.
'As this process continues, it would not be right for me to comment further on this matter. Meanwhile, my family and I will continue in our duty and service to you all.'
Police officers were pictured at the entrance to Wood Farm on the King's private estate
It is the fourth day that police have been searching the home where Andrew lived for 22 years
Pressure is now mounting for Andrew to be removed from the line of royal succession.
Andrew had his royal titles removed last year over his links to Epstein but remains eighth in line to the throne.
Labour MP Luke Pollard said it was 'the right thing to do' and confirmed that the Government was actively considering legislation to remove his right of succession once the police investigation into him had been concluded.
Liberal Democrat leader Sir Ed Davey said the case of Andrew is something MPs will have to consider 'when the time is right' to make sure he cannot become king.
'The most important thing right now is that the police be allowed to get on with their job, acting without fear or favour,' he said.
'But clearly this is an issue that Parliament is going to have to consider when the time is right, naturally the monarchy will want to make sure he can never become king.'
Andrew Bowie, a senior Tory MP, said it would be 'the decent thing' for Andrew to now voluntarily give up his place in the line of succession.
'I think it would be the decent thing,' the shadow Scotland secretary said.
Pressure has been building to remove Andrew from the line of succession, the former duke is currently eighth in line to the throne
'Of course, if he's found guilty of this, I think Parliament would be well within its rights to act to remove him from the line of succession.
'But, let's remember, he's not been found guilty of anything just yet – he has yet to be charged with anything.'
Constitutional experts said it would be a complex process to pass legislation to formally remove Andrew from the line of succession.
An Act of Parliament would be required to remove Andrew along with the support of the 14 Commonwealth countries where the King is Head of State, including New Zealand, Canada and Australia, where legislation would also be needed.
On Friday night, Chief Secretary to the Treasury James Murray confirmed that the Government was ‘considering any further steps that might be required', and are not ruling anything out.
Supporters of the legislation point out that it is feasible that, although he is only eighth in line, he could become a Regent to William's children in extreme circumstances if anything were to happen to both King Charles and Prince William.
He had stepped down from public duties back in 2019 over allegations about his friendship with Epstein, in the wake of his disastrous Newsnight interview.
But pressure has grown for further action following continued allegations about Andrew after the further release of documents and photographs from the Epstein Files.
Andrew has always denied any wrongdoing but has not directly responded to the latest allegations.
