FREETOWN, August 29, 2008 (AFP) - The brother of one of almost two dozen people arrested in Sierra Leone over the country's biggest ever cocaine haul alleged Friday that they were being abused in detention.

Oumar Farouk Sesay sent a petition complaining of 'inhuman treatment and violation of the right of the prisoners' to Sierra Leone's human rights commission.

In all 22 people, including nine South Americans, have been detained since police found 600 kilos (1,320 pounds) of cocaine in a Venezuelan plane bearing a fake Red Cross emblem at Freetown's international Lungi airport on July 13.

The petition said, 'the national outcry against the detainees has been used as an excuse to trample on their rights and a leeway for executive intrusion in the process never before seen in Sierra Leone even in treason cases.'

He alleged, 'harassment of defence lawyers, imposition of a 23-hour daily lock-up of the detainees and denial of access to medical treatment to two of the men in detention.'

Prison director Henry Showers rejected the charges saying, 'the suspects are being kept under normal detention regulations.'

A spokesman for the human rights commission, Joseph Cole, said the petition was being studied and any appropriate action would then be taken.

A record for Sierra Leone, it was one of the biggest drugs hauls in West Africa this year. According to local authorities, the street value of the cocaine seized is 200 million dollars, or 125 million euros.

West Africa has become an important transit point for cocaine from South America bound for European markets.

But Sierra Leone is toughening up its drugs laws and recently passed a National Drugs Control Act which raised the maximum sentence for cocaine trafficking to life in prison.