China has upheld the independence and integrity of its justice system, as would any other country, in the trial and execution of British drug smuggler Akmal Shaikh, say legal experts, refuting criticisms of China's human rights record and lack of clemency.

Shaikh, a 53-year-old British man, was executed by lethal injection on Tuesday in Urumqi, capital of northwest China's Xinjiang Uygur Autonomous Region.

He had been convicted of carrying up to 4,030 grams of heroin at Urumqi International Airport from Dushanbe, capital of Tajikstan, on September 12, 2007.

China's Criminal Law stipulates that the trafficking of more than 50 grams of heroin is punishable by death.

"According to China's Criminal Law, the death sentence given to him is legitimate and it has nothing to do with human rights concerns," said Wang Mingliang, professor of criminal law at Shanghai-based Fudan University.

"Some Western countries also retain capital punishment, and its existence does not equate to a lack of human rights," Wang said.

Xue Jinzhan, professor of criminal law at the East China University of Political Science and Law, also in Shanghai, said the administration of the death penalty related to a country's history, culture and other conditions.

China strictly enforced the law without discrimination in handling the case, Chinese legal experts told Xinhua.

"It's human nature to plead for a criminal who is from the same country or the same family, but judicial independence should be fully respected and everyone should be equal before the law," Xue said.

Wang said it could be understood that British media ran emotional stories and local people reacted with sorrow or anger as Britain did not retain the death penalty.

"But one country should respect judicial independence of another country, without any interference in internal affairs," Wang said.

"Shaikh's case serves as a testimony to China's judicial justice, which deserves full respect from other countries."