They used to say the Mumbai police is next only to Scotland Yard.

But tough days have befallen the pride of the Mumbai police -- the Crime Branch, famed for its unusual detection methods.

High-profile detectives who played a major role in controlling gangland activity are either under arrest or in trouble.

Former joint commissioner of police Sridhar Vagal and deputy commissioner of police Pradeep Sawant have been arrested in the Telgi scam.

Assistant Police Inspector Sachin Vaze -- one of the city's so-called encounter 'specialists' has been arrested on charges of murdering Khwaja Yunus, an accused in the Mumbai bomb blasts case.

Another encounter 'specialist' Sub Inspector Daya Nayak is under the scanner for allegedly having links with the underworld. Ever since Nayak was cut down to size, encounter killings in Mumbai have come to a halt.

Senior Police Inspector Pradeep Sharma has the last encounter killing, in Malad, northwest Mumbai, in January, to his name.

The Mumbai police's Crime Branch has a force of around 1,300 men, who are controlled by Joint Commissioner of Police Dr Satyapal Singh.

The allegations against its officers have understandably affected morale. Sources told rediff.com that informants have been avoiding getting in touch with Crime Branch officers and men.

The detection unit at the Crime Branch is considered to be the most important as it directly deals with the underworld and terrorists. Fourteen units, like the crime intelligence unit, fingerprint unit, directly work with the detection unit.

Most of the arrested officers belong to the detection unit. The expertise of these officers, sources say, is the key to keep the underworld in control.

"To deal with the underworld one should have a good network of informants. Network and interrogation techniques are the two most important instruments of the Crime Branch. A policeman is not a god. They get information about the underworld and terrorist activities through informers," a top police officer told rediff.com

"Informers start coming to you only after you win their confidence, which is a long process. An informer giving you information is putting his life at risk. So they want to check you out very well."

He said the network assiduously built by officers comes to nought if they are abruptly transferred or if an officer comes under the scanner.

"To make the Crime Branch professional one has to make an officer an expert in a particular area and build up the department with other officers with similar skills," a police officer said.

Another setback for the Crime Branch was the abrupt transfer of one of its stars, Additional Commissioner of Police Rakesh Maria, who was initially asked to lead Mumbai's anti-terrorist squad. Maria was transferred to the anti-corruption bureau as Special Inspector General of Police, where his network of informants was of no use.

"The Mumbai underworld is mostly dominated by Pakistan and Dubai-based gangsters. Due to the Crime Branch's efficiency and American pressure on Pakistan and other countries gangsters based abroad have been pressurised not to send money to their Mumbai bases. That is the reason why these boys have started indulging in robbery," a top police officer explained.

Deputy Commissioner of Police (detection) Dhananjay Kamlakar told rediff.com: "Allegations about Crime Branch officers is not new. Some allegations may be genuine, but some are made by vested interests. Since the Branch confronts one allegation after another continuously there is an impression that we are undergoing a bad phase."

"The activities of the underworld and terrorists are under control because of the Crime Branch's efforts," Kamlakar said. "We are working on a professional way to maintain the pride of the Crime Branch."