A police reform proposal to have investigators work without the interference of powerful bosses has been met with criticism that such a plan is not practicable.

Among those not convinced by the idea is Manich Suksomchitra, who is working closely with a group of experts under the police reform committee to draft a so-called "zero interference" measure.

Senior officers have expressed similar scepticism.

The experts suggested a number of measures which neededc to be taken to reform the field of police work known as sob suan.

Unlike outdoor criminal suppression efforts, this area of police work is more paperwork-driven and inquiry- and law–intensive.

It deals with complaints and investigation findings, with police forwarding them to prosecutors and the courts.

To reform sob suan, officers must have the requisite expertise, be ensured of a good career path and, above all, granted more freedom to work without interference from their superiors, they say.

In a recent interview with the Bangkok Post, Mr Manich, chairman of the public relations panel under the police reform committee, admitted it would be "difficult to make sob suan investigations completely free from high-ranking officers."

His committee has suggested a nine-member panel be set up to monitor irregularities.

The group, made up of three special branch police officers and six non-police experts, will handle people's complaints over unfair treatment.

Its role would be to head off any attempts to intervene in investigations.

Such freedom to operate unconstrained is crucial, according to Pol Lt Col Kritsanaphong Phutrakun, a lecturer of police science at the Royal Police Cadet Academy.

Otherwise, criminal cases can go off-track if local police station chiefs abuse their power in preparing investigation reports for prosecutors, he added.

Police station chiefs are authorised to look through investigation results, giving them the power to overrule them.

Proponents of reform are aware that different opinions between police investigators and their bosses can occur. It has been suggested that a police commander with no direct role in the case should be permitted to settle any disputes.

However, even this would not guarantee that there would be no interference with the work, said Pol Col Suwat Saengnum, chief of the Crime Suppression Division's sob suan unit.

Officers only come up with initial investigation results. Whether they proceed to court still largely depends on prosecutors, he added.

Bearing in mind such concerns, many senior police officers are sceptical of the proposed reform.

Pol Col Uthen Uniphin, chief of the Metropolitan Police Bureau's Training Centre, said giving young or inexperienced investigators too much freedom may not be always a good idea, expressing concern that such officers might not exercise enough caution when conducting investigations.

Despite all this, reform is much needed, Mr Manich said.

The Royal Thai Police require capable officers to fill more than 1,600 vacant jobs in this field, he said. Without a bright career path it would be hard to attract new recruits.

The proposal also suggests sob suan merge with sueb suan, or outdoor criminal suppression, he added.