Image copyright Irish Defence Forces Image caption The Irish naval vessel - the LÉ Niamh, sails alongside the detained yacht Makayabella during the operation that took place about 300 miles off the south west coast of Ireland

Four British men have appeared in court charged with drugs offences after the seizure of more than a tonne of cocaine off the Irish coast on Tuesday.

The drugs haul has an estimated street value of more than £100m, according to the UK's National Crime Agency (NCA).

It was seized when the Irish navy intercepted a yacht off the Cork coast. Three men arrested on board have been charged with drug trafficking in Cork.

A fourth man in the UK has been charged with conspiracy to import cocaine.

Stephen Powell, 47, of Netherfield Road, Guiseley, Leeds, was arrested on Thursday during a NCA follow-up operation in West Yorkshire.

He appeared at Leeds Magistrates' Court on Saturday, where he was remanded in custody.

The seizure is believed to be one of the largest drug finds at sea in Europe this year.

Mr Powell's elderly father was among the three men who were arrested on board the yacht.

The trio were brought before a special sitting of Cork City Court on Friday evening.

The accused are 70-year-old John Powell, with an address at Airedale Mews, Silsden, West Yorkshire, 28-year-old Thomas Britteon, of Convamore Road, Grimsby, and Benjamin Mellor, 35, from Mornington Villas, Bradford.

All three face a single charge of trafficking of cocaine on a ship at sea with intent to import the drug.

The yacht they were travelling on, called Makayabella, was intercepted about 200 - 300 miles west/south-west of Mizen Head during the early hours of Tuesday.

Their vessel had been under "covert surveillance" by the Irish navy, who carried out a joint arrest operation with the Irish Revenue Customs Service and police (An Garda Síochána).

Image copyright PA Image caption Members of the Irish navy stand guard over more than a tonne of cocaine seized from a yacht off the coast of County Cork on Tuesday

The Irish authorities were acting on intelligence provided by the British NCA and the French customs service DNRED.

In its follow-up operation in West Yorkshire, NCA investigators also arrested a fifth man, aged 43.

The fifth suspect was detained on Wednesday, but has since been released on bail, pending further inquiries.

The NCA also seized a motorboat, believed to be linked to the alleged drug trafficking operation, at a marina in Gwynedd, north Wales.

At Cork City Court on Friday evening, all three defendants were remanded in custody until Thursday 2 October, when they are due to appear again via video link.

The judge at Leeds Magistrates' Court remanded Stephen Powell in custody, to appear at the city's crown court on 13 October.