Face of Nation : Dorset Police made the announcement on Wednesday evening and confirmed the man, from North Yorkshire, has been quizzed by detectives.
The Argentine striker, 28, died when the Piper Malibu aircraft he was flying in crashed into the English Channel on January 21.
He died a little over a day after signing for then-Premier League team Cardiff who had snapped him up for a club record £15million from French side Nantes.
An inquest showed he died from “head and trunk” injuries.
His body was brought to Portland Port in February and detectives from Dorset Police have been carrying out enquiries into the circumstances of the death on behalf of HM Coroner.
The body of pilot Dave Ibbotson, 59, from Crowle, Lincolnshire, was never found.
Detective Inspector Simon Huxter, of Dorset Police’s Major Crime Investigation Team (MCIT), confirmed the man was arrested on suspicion of manslaughter by an unlawful act.
He said: “We have carried out a wide-ranging investigation into the circumstances of the death of Mr Sala and continue to work with partner agencies including the Civil Aviation Authority.
“As part of this investigation we have to consider whether there is any evidence of any suspected criminality.
“As a result of our enquiries we have today arrested a 64-year-old man from the North Yorkshire area on suspicion of manslaughter by an unlawful act.
“He is assisting with our enquiries and has been released from custody under investigation.”
Earlier this month, Wiltshire Police said two people would face charges over a photograph showing Mr Sala at the Holly Tree Lodge mortuary in Bournemouth.
Sherry Bray, 48, has been summonsed for three counts of computer misuse, perverting the court of justice and sending an indecent/offensive message.
Christopher Ashford, 62, has been summonsed in relation to six counts of computer misuse.
The pair, who were arrested in February, will appear before Swindon Magistrates’ Court on July 10.
