THE wife of Lord Lucan will reveal all about the night of his disappearance in a new documentary.

Dowager Lady Lucan has refused to co-operate with numerous film makers’ requests since the night of her husband’s disappearance in 1974.

However, the 79-year-old has agreed after being offered £56,000, according to the Sunday Express.

Lucan tried to bludgeon his wife to death at their Belgravia home on the same night he killed their nanny, Sandra Rivett, 29. It is thought he mistook her for his wife. The pair had been in a bitter custody dispute over their three children.

Following the attack the Dowager ran to a nearby pub, covered in blood, crying for help.

Lucan disappeared, with his blood stained car found abandoned in Newhaven.

There have been numerous reported sightings over the years and multiple theories suggesting he is still alive. The Dowager, however, believes he threw himself off a boat in the English Channel early the next morning.

As part of the documentary she is expected to reveal all about the fateful night. She has been spotted filming at a number of locations around the country, including at the Kensington church in which they married.

A friend told the Express she had agreed to do the documentary partly as an act of revenge against her son. Her children have not spoken to her since she suffered a mental breakdown. A screening date has not been set.