The shocked and heartbroken mother of a former US soldier, who shot dead six Sikh worshippers at a Milwaukee gurdwara, on Tuesday said she was sorry for her ‘precious little boy’ turning into a mass murderer.

Laura Lynn said that she has had no contact with her 40-year-old son since she and his father Jesse Alvin Page divorced. She said she was shocked and heartbroken after hearing about her son's death.

"He was such a precious little boy, that's all I can say, he was a very fun-loving, typical little boy. He was just a very soft spoken, gentle young man," she told Mail Online.

"... I'm devastated. My heart goes out to all the people who lost their loved ones, that's all I can say, I am so sorry."

Asked if the army had changed her son, she said: "I have no idea; I had not been in contact with him that much. Actually in the last 12 years I have not been in contact with him at all since his dad and I divorced."

Wade Michael Page, a 'neo-Nazi', was dismissed from the army in 1998 after serving six years following a 'pattern of misconduct'.

Page, a ‘white supremacist’ and a ‘skin head’, had gunned down six people in the Milwaukee gurdwara, Wisconsin on Sunday. Pictures show him heavily tattooed.

His neighbours said he had a tattoo commemorating the September 11, 2001 terrorist attacks on his right arm, a common indicator of far-Right and anti-Muslim affiliations.

FBI looking into slayer's links with white supremacist groups

The FBI was on Tuesday looking into the links of the white gunman involved in the Gurdurwara shooting to white supremacist groups with a history of hate towards Jews and black people but ruled out participation of a second person in the attack.

As more details emerged former US army psychological- operations specialist Wage Michael Page's 'neo-Nazi' leanings, the FBI on Tuesday intensified its probe to ascertain the motive behind the killing of the six Sikh worshippers.

Page's neighbours said he rarely left his one-bedroom house where he lived alone, and never made eye contact, but civil organisations which monitored his actions, described the 40-year-old as a 'frustrated neo-Nazi', who had been leader of a racist white-power band.

The FBI said they were looking into Page's ties to white supremacist groups but insisted there were no prior warning signals that could have led investigators to believe he was plotting something so vicious.

Special Agent Teresa Carlson, head of the Federal Bureau of Investigation's Milwaukee office, said the gunman was the subject of a 'domestic terrorism' probe.

The FBI also ruled out the involvement of a second person in the Sunday shooting, hours after releasing the picture of a 'person of interest'.

Officials cleared the man after interviewing him and affirmed that the slaying was the handiwork of a lone gunman.

"The unidentified subject has been located, interviewed and does not appear to be connected with the shooting incident at Oak Creek," a FBI spokesman said.

Earlier on Monday at a news conference, the FBI said they were trying to identify a suspicious man who arrived at the scene after the shooting and released a photograph of him, asking for the public's help.

It emerged from disconnected pieces of information that the ex-army veteran regularly attended hate events, was an ardent believer in the white supremacist movement and was associated with rock bands whose violent music talked about murdering Jews and black people.

He played in white supremacist heavy metal bands with names such as 'Definite Hate' and 'End Apathy'.