PC Andrew Massingham, 41, was this week acquitted of causing the death of Bolton-le-Sands grandfather Peter Williams, 67, by dangerous driving during a police training exercise.

His colleague, PC Sean Schofield, 38, was also acquitted of the charge but was banned from driving for two years and fined £500 after being found guilty of an alternative charge of careless driving.

While Mr Williams' family have expressed forgiveness to PC Schofield, whom they hugged and comforted after the three-week hearing at Liverpool Crown Court, they told of their anger after hearing how PC Massingham had been caught driving off-duty in Yorkshire at 92mph.

He pleaded guilty to that offence in January and was banned from driving for 28 days. A family statement after the trial said: "The behaviour of PC Massingham felt like a betrayal to the concern and courtesy that we had offered him and his family.

"The sense of futility surrounding our father's death was heightened significantly on learning of his speeding offence.

"We have difficulty in expressing the extent of our anger in response to this and the distress that it caused.

"Such behaviour was immensely disrespectful to our father and his memory, serving simply to make it appear futile and wasted."

Mr Williams' son Geoff, a senior pastor at a Free Methodist church in Preston, said: "We offer our forgiveness but in order to receive it he needs to be genuinely remorseful and we are not convinced we have seen that."

He added that Massingham should never return to duty as a traffic officer.

The jury said it believed Lancashire Constabulary was guilty of 'institutionalised complacency' in its driver training and said PC Massingham should share responsibility for the accident.

Peter Williams' widow Jean, 65, who lives in Mill Lane, Bolton-le-Sands and is a prayer leader at the Lancaster Free Methodist Church in Queen Street, said: "The loss of my husband has been devastating in so many ways. I don't think I can express in words how Peter's death has affected me."

Mrs Williams and her husband were on their way to the Yorkshire Dales for a break, when the accident happened on the B6254 near Over Kellett on November 2, 2006.

The trial heard how PC Schofield collided with their car after losing control of his Volvo on a left-hand band.

He had been following PC Massingham as part of a training exercise to test a speed measuring system.

A black box device showed PC Schofield hit speeds between 65 and 104mph in the 30 seconds before the crash, while PC Massingham clocked between 86 and 95mph.

Mr Williams, who has another son Brian, who lives in Scotland, died in the Royal Lancaster Infirmary the day after the accident, while his wife suffered two broken wrists.

The Independent Police Complaints Commission will now hold discussions with Lancashire Constabulary to determine whether there will be any disciplinary action taken. Both officers are currently on 'alternative duties'.