A senior Morrisons employee has been arrested over allegations of insider trading reportedly in relation to the launch of its online grocery operation with Ocado.

Paul Coyle, group treasurer and head of tax at the Bradford-based supermarket, was held last month in Harrogate, North Yorkshire, as part of an investigation by the Financial Conduct Authority (FCA).

According to the Daily Telegraph, the allegations relate to dealing in Ocado shares before the tie-up between the two retailers was announced. The agreement has sent the stock soaring.

The newspaper said Mr Coyle, who has not been charged, has not returned to work since the arrest.

Morrisons is using Ocado’s technological know-how to make its belated debut in internet deliveries, which finally began earlier this month.

It announced in May that it had signed a 25-year deal with Ocado to acquire its distribution centre in Dordon, Warwickshire, for £170million and use its technology.

The FCA said in a statement on December 12: “The Financial Conduct Authority with the assistance of the North Yorkshire and West Yorkshire Police has this morning executed a search warrant in Harrogate.

“One male, aged 49, has been arrested and is currently in custody to be questioned in connection with an investigation into insider dealing and market abuse.”

North Yorkshire Police said a 49-year-old man arrested in December was released on police bail until March 19.

Morrisons declined to comment after Mr Coyle was named by the Telegraph today. Mr Coyle was unavailable for comment.

The grocer has endured a miserable start to the year after reporting a 5.6% slide in like-for-like sales over Christmas.

It is also reportedly being targeted by activist investors who want it to improve its performance and are pushing for it to sell off property to raise cash.