Police investigating the death of Emiliano Sala have arrested a 64-year-old man from North Yorkshire on suspicion of manslaughter by an unlawful act.
His body was brought to Portland Port in Dorset on January 7, with police investigating the circumstances of his death.
Detective Inspector Simon Huxter, of Dorset Police, 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 and as a result of our inquiries we have today, Wednesday, June 19 2019, arrested a 64-year-old man from the North Yorkshire area on suspicion of manslaughter by an unlawful act.
"He is assisting with our inquiries and has been released from custody under investigation."
Family liaison officers have been updating the families of Mr Sala and David Ibbotson, the pilot of the plane that lost contact with Air Traffic Control north of Guernsey.
The body of Mr Ibbotson, 59, from Crowle, Lincolnshire, who was flying the plane from Nantes in France to Cardiff on January 21, has not yet been located.
Detective Inspector Huxter added: "This matter therefore is still subject to a live investigation and I would ask the media and members of the public to refrain from speculation, as this could cause additional distress to the families involved as well as potentially hinder the investigation.
"As is standard practice, we will not be releasing any further information as to the identity of the individual who has been arrested unless that person is charged to appear in court and again would discourage any speculation in relation to this."
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.