A man who tried to rob his son in a £4.5m "perfect robbery" has been jailed for 20 years.
Carpenter Martin Williams told a gang about a cocaine deal his son Shane was involved in and the gang then tried to steal the drugs, the Old Bailey heard.
Williams, 60, of Warden Bay on the Isle of Sheppey in Kent, and three other men were found guilty of conspiracy to rob and conspiracy to supply cocaine.
His son and an accomplice were given 20 years for conspiracy to supply drugs.
The court heard a three man gang raided 36-year-old Shane Williams' flat and knocked out him and his accomplice Nicholas Smith, also 36, with a crowbar and a stun gun.
But they were arrested by an undercover police team watching the address from outside as they tried to escape with 78kg of drugs.
Prosecuting solicitor Sallie Bennett-Jenkins told the court: "It was a perfect robbery, a victimless robbery, because what drug dealers complain to the police of being robbed?"
Shane Williams, of Thornhill Road, Warden Bay, and Nicholas Smith, of Clyde Avenue, Sanderstead, Surrey, were both jailed for 20 years for conspiracy to supply cocaine.
Martin Williams, also of Thornhill Road in Warden Bay; Raymond Dyson, 57, of Shrublands Avenue, Croydon; William Parker, 45, of Greenhithe Lane in Carshalton; and John Walton, 47, of Maxwell Close in Croydon, were all convicted of conspiracy to rob and conspiracy to supply cocaine.
Dyson and Walton were also found guilty of possession of a firearm, with Parker cleared of that charge.
Martin Williams was jailed for 20 years, Walton for life, Parker for 23 years and Dyson for 18 years.