ACCRA, Feb 5 (Reuters) - Five Europeans detained after police seized a record haul of cocaine in Ghana could face up to 40 years in jail in local prisons if found guilty, the West African country's attorney general said on Thursday.

The remarks came as Ghanaian officials slammed a judge's decision this week to grant the five men bail of 300 million cedis ($32,258) each.

The accused -- four Britons and a German -- are due to reappear in court in the former British colony on February 10.

"This is a very serious matter with an international dimension, and it's important that we demonstrate that we in Ghana are serious about drug smuggling," said Attorney-General Papa Owusu-Ankomah, whose department is heading the prosecution.

"We'll push for the maximum sentence for these people, and that could be 40 years in our local prisons," he said, adding that the prosecution planned to appeal the bail ruling.

The Europeans were arrested last month after 674 kg (1,486 lbs) of cocaine worth $145 million were found packed into 22 parcels and hidden in a secret compartment behind a mirror at the home of Kevin Gorman, 59, in the port city of Tema, east of Accra.

The other British suspects are David Logan and Frank Laverick, both 43 and directors of a company called Ocean Maritime in Gibraltar, and Alan Hodgson, a retired building manager from Wales. German Sven Herb, 45, was also detained.

Gorman, who holds dual British and American citizenship, was charged with possession of drugs, while the four others were charged with aiding and abetting. One Ghanaian is being held.

Lawyers for the accused said they were still in prison on Thursday, pending administrative procedures by the court.

The decision to grant bail was greeted with anger by senior government officials.

"I'm not a lawyer, but speaking as an ordinary Ghanaian, I believe this is wrong, and I'm very angry," Interior Minister Hackman Owusu-Agyeman told Peace FM radio on Thursday.

"These people could go and influence potential witnesses. By treating the case so lightly, the resolve of our narcotics officers could simply be damaged," he said.

The arrests came after a six-month sting operation involving British, Antiguan, Spanish and Portuguese authorities following the seizure last September of $74 million worth of cocaine in the Azores.