Police have begun a fingertip search for human remains in the garden of a New Addington house which was once occupied by a convicted paedophile.

The move follows an anonymous letter sent to a family who moved into the house in Walton Green.

The letter alleges human remains were buried at the house 35 years ago, believed to belong to two young children.

At a press conference outside the address yesterday, Tuesday, police confirmed they were acting on an anonymous letter which they received 12 months ago.

They said that the letter's author is now being looked after by family liaison officers.

The fingertip search of the property started today, while an excavation of the site would start on Monday, August 14.

Police are also searching the missing persons register from 35 years ago.

The house is the former residence of 72-year-old paedophile Leslie Ford-Thrussell who was jailed for 12 years in June 2004 for a string of sex offences on nine girls, some as young as six.

The former landscape gardener was convicted of seven counts of rape and 23 counts of indecent assault over a period of 17 years.

He targeted some of his victims as they went to school, offering them sweets, and videotaped some of the abuse, Croydon Crown Court heard during the June 2004 case.

However Ford-Thrussell was not thought to be living at the address 35 years ago and police say they are uncertain whether an offence had been committed.

Detective Chief Inspector Mark Stockford said officers investigated the letter over the last year and that information given to them by the letter's author gave "additional weight" to the inquiry.

He said: "We are ruling nobody in or nobody out of the investigation."

Neighbours told the Croydon Guardian that the family had moved out of the council-owned house around a month ago and said it had been a "very hush-hush operation".

One neighbour, whose balcony overlooks the garden said: "The family that were living there got moved out about a month ago, nobody knew why they had gone. I would have thought that police have known about this for quite a long time, they have completely scanned the area."

One woman, who lives next door to the address, said: "All this is quite disturbing, I am more concerned for the people who have young children. If I had known all of this during the time my son was growing up I definitely would have watched him more closely, I am just glad that nothing happened."