London, UK - The UK's Metropolitan Police said Thursday it had referred itself to a watchdog after failing to tell other authorities about a letter making serious accusations against Meghan Markle's father.

The country's largest police force said in a statement that after an internal review, it had submitted itself to the Independent Office for Police Conduct watchdog over its "decision not to inform other law enforcement agencies."

Instead, the force passed the letter to Meghan, Prince Harry's wife.

The Met Police late last week confirmed it had received a letter in January 2019 making claims about alleged offending outside the UK related to Thomas Markle.

This came after Meghan said she had seen a letter sent to the police force making "troubling and disturbing allegations against my father" and received promises that they would be investigated.

British newspapers reported last week that Thomas Markle's son, Thomas Markle Jr., had found child abuse images among his father's possessions at his former home in the Philippines.

Thomas Markle has denied all the claims.

Commander Adam Slonecki, head of the Met's protection command, added in a statement that "a number of referrals" about the allegations were being made to "relevant overseas law enforcement agencies."

Philippine police found child pornography materials at Thomas Markle's former home and are investigating a laptop, the country's interior minister, Jonvic Remulla, told AFP this week.

Meghan's father had been living in Cebu in the Philippines until reportedly returning to the US earlier this year.

A spokesperson for the FBI said it was "aware of the allegations and will provide support, as appropriate, to the Philippine authorities."