Newspaper Ekstra Bladet reported that Knudsen, 25, had been arrested and charged with the murder of his girlfriend, 33, after he allegedly stabbed her to death in the bedroom of their apartment.
The woman's two young children were in the apartment at the time of the killing.
On January 22, 2013, Knudsen was allegedly shot at by Australian biker John Cohen who, with his partner Mark Shea, had been looking for the Dane and spotted him on the back of a motorbike taxi. The incident happened on Soi Sansabai in Patong.
Cohen missed Knudsen and instead hit two innocent German tourists, who had to be hospitalised with arm and shoulder wounds.
After their arrest, Cohen and Shea said Knudsen owed them a million baht – B380,000 for a big bike and the remainder in interest – and had paid them nothing. Earlier a court confirmed that they were entitled to the sum.