Image caption Kieron Bryan says he spends 23 hours a day in his cell

A British journalist detained in Russia after a Greenpeace protest has said he fears "losing years of his life" being kept away from his family and friends.

Video journalist Kieron Bryan, 29, from London, was one of 30 people arrested on boat Arctic Sunrise at an offshore oil drilling rig on 18 September.

He is one of six Britons charged with hooliganism.

In a letter to the Sunday Times, Mr Bryan, originally from Devon, described his treatment as "ludicrous".

The group of 30 - 28 activists, a photographer and video journalist Mr Bryan - had originally been charged with piracy, but Russian authorities dropped the charges last week, replacing them with hooliganism charges.

That new charge has a maximum penalty of seven years rather than 15.

Greenpeace denies any wrongdoing and is calling for the release of the detainees - who come from 18 countries - and the Arctic Sunrise.

So far all bail applications in the case have been refused.

'Terrifying'

I spend 23 hours a day in here with nothing but the occasional book and my thoughts Kieron Bryan

In his letter, Mr Bryan said: "My greatest fear is being kept from my family, my friends and my girlfriend for any great length of time.

"In many ways I'm lucky I don't have children who depend on me, but the fear of losing years of my life and the opportunity to perhaps start a family is terrifying."

He said the hardest moment he had faced was his first night in prison when the group was split up and placed in different cells.

"Now the difficulty is the silence and ignorance imposed by our detention," he said.

He described his cell as 26ft long, 13ft wide and 20ft high.

"I spend 23 hours a day in here with nothing but the occasional book and my thoughts," he wrote. "We are granted an hour a day for exercise which is held in a shed about 30 metres from my cell. If I'm lucky I might get to shout a quick hello to an English speaker."

He also described some of the food provided. Lunch - soup and a fish stew - "tastes like an ashtray full of seawater," he said. Another dish "is clearly boiled from breakfast onwards".

The other Britons being held are activist Philip Ball, of Oxfordshire, logistics co-ordinator Frank Hewetson from London, activist Anthony Perrett from Newport in south Wales, communications officer Alexandra Harris, originally from Devon and 2nd engineer Iain Rogers, from Exeter.

All 30 people who were on board the ship are in pre-trial detention in the northern port city of Murmansk until 24 November. They have complained of being held in harsh conditions.

They were detained when Russian security sources stormed the ship five weeks ago following a protest against drilling for oil in the Arctic.

Eleven Nobel prize-winners have written to Russian President Vladimir Putin, urging him to drop the charges of piracy.

The Netherlands took the case of the Dutch-flagged ship and its crew to the UN tribunal in Hamburg on Monday.

The Russian foreign ministry released a statement pointing out that Moscow had opted out of UN Law of the Sea dispute procedures, which infringe upon sovereignty, in 1997.