(Updates with anti-graft agency decision on case against Yingluck)
By Amy Sawitta Lefevre
BANGKOK, July 17 (Reuters) - Thailand's military rulers have given permission to former Prime Minister Yingluck Shinawatra to travel to Europe where she is expected to attend the birthday party of her brother Thaksin, also a deposed former premier, officers said on Thursday.
A military spokesman said Yingluck, forced from office by a court ruling days before the military seized power in May, was permitted to leave provided she stayed out of politics. He said she would be allowed back into Thailand at the end of her trip.
The military briefly detained Yingluck and hundreds of other politicians, activists, academics and journalists after the May 22 coup, which it says it staged to restore order after months of sometimes violent protests against her government.
Some of those detained remain in custody under martial law while the military's National Council for Peace and Order has banned hundreds of others from leaving the country. It has also stifled dissent and dispersed anti-coup protests.
"Yingluck has not done anything that violates our orders so her personal trip to Europe has been approved," said army spokesman Colonel Winthai Suvaree.
"Yingluck is not a wanted person. Of course we will allow her back into the country. Why would we not?"
Several hours later, the national anti-corruption agency said it would forward a criminal case against Yingluck, related to a loss-making state rice-buying scheme, to the attorney general. If the case is forwarded to a court and she is found guilty, Yingluck could face time in jail.
It was not clear if the decision by the National Anti-Corruption Commission (NACC) decision to forward the case would have any bearing on Yingluck's travel plan. The commission said the decision to let her go abroad was the military's.
Earlier, General Teerachai Nakwanit, army commander for the region which includes Bangkok, told Reuters Yingluck was expected to attend the 65th birthday party in France this month of Thaksin Shinawatra, removed by a 2006 military coup.
Thaksin has lived in self-exile since 2008 to avoid serving a sentence for corruption.
The ouster of Yingluck's government was the latest twist in a decade-long power struggle pitting Thaksin, who gained widespread popularity for providing social benefits in impoverished rural regions, against the royalist-military establishment.
For six months before the coup, Thailand was convulsed by establishment-backed protests aimed at ousting Yingluck, who became Thailand's first female prime minister when she swept to power in a 2011 election.
Protesters wanted to eradicate the influence of her family, including Thaksin, a former telecommunications billionaire. He is free to return to Thailand, but faces the prospect of time in prison if he does.
At least 30 people were killed in sporadic violence over the months of unrest and the economy was badly bruised.
The United States and European Union have led international condemnation of the army's seizure of power and downgraded diplomatic ties.
At the junta's request, the foreign ministry has revoked the passports of at least six people, including two anti-coup movement founders who fled the country.
Yingluck, 47, has been under investigation by Thailand's anti-corruption agency over a rice-buying programme which offered farmers a price for their rice well above the market level.
Wicha Mahakun, a member of National Anti-Corruption Commission, said the agency would forward her case to the attorney-general who would consider whether to pursue criminal charges against Yingluck for dereliction of duty.
"It is important for the prime minister to consider policy carefully but the defendant chose to continue the scheme which caused huge damage to the state," Wicha told reporters.
The scheme was at the heart of her government's populist policies, but caused huge financial losses to the state. The military is conducting nationwide inspections of rice warehouses to assess the extent of corruption related to the scheme. (Reporting by Pracha Hariraksapitak; Writing by Amy Sawitta Lefevre; Editing by Robert Birsel and Ron Popeski)