Many officials of a particular batch have been serving as the OSD for a long time because the ruling BNP believes they are loyal to the previous regime, said an official of the establishment ministry, preferring not to be named.

Official statistics show that currently more than 350 officers of different levels, the highest ever at a time, are serving as the OSD.

But another senior bureaucrat defended the government's stance on the issue terming the rise a temporary phenomenon.

"The OSD is a recognised position and is included in the organogram of the government. It was created to meet administrative requirements," he said. "The provision for appointing an officer as the OSD was there in the past and will exist in future also. The system is followed all over the world."

Talking to The Daily Star yesterday, he said the officials were made the OSD for various valid reasons.

"This is a very temporary arrangement. The officers who have been serving as the OSD for a long time are either facing charges of corruption or are highly inefficient," he claimed.

He said it has been witnessed in recent years that a section of civil servants have become highly politicised and they serve the party of their choice, when it is in power, like its activists.

"These partisan officers remain the OSD for a long time. When another party comes to power and it does want them to have any role because of their past record," he said.

Some senior officials of the Ministry of Establishment however said the number of the OSDs is currently very high because 500 officials have been promoted to the rank of deputy secretary against 150 vacant posts.

It would take some more time to solve the problem because there is lack of the required number of vacancies.

Sources said there are instances that some officials were given posting three or more times, but the ministries or departments concerned did not accept them because of their previous service record and as a result, they remain the OSD for a long time.

Establishment ministry sources said there are also officials who are not physically and mentally fit for holding important positions because of illness.

"There are many in the administration who are continuing their jobs purely on humanitarian ground," he said. "The World Bank has been pressing the government to downsize the administration. It is possible to retrench a good number of officials on valid grounds, but the government is still keeping them in service as the OSD for humanitarian reasons."