Moscow, May 8 (IANS/RIA Novosti): A man and his son have been held by the US authorities for trying to send machinery which could be used to produce weapon of mass destruction (WMD) in North Korea.

According to the US officials, a Taiwan resident with suspected ties to North Korea has been charged together with his son with seeking to bypass a US ban on the export of weapons machinery to Pyongyang with the aim of helping the country obtain WMD.

Hsien Tai Tsai, 67, was arrested last Wednesday in Estonian capital Tallinn, a statement by the US Attorney’s Office in Chicago said Monday.

His son Yueh-Hsun Tsai, 36, was arrested the same day at his home in Illinois, it added.

Tai Tsai had previously been banned from doing business in the US for his role in a North Korean weapons procurement channel.

But the younger Tsai allegedly helped his father to evade the ban by conspiring to continue shipping machinery that could be used to produce WMD in North Korea.

The two are now accused of conspiracy to defraud the US in its enforcement of laws against the spread of WMD, conspiracy to violate the International Emergency Economic Powers Act and money laundering.

The investigation has revealed that the suspects are associated with at least three Taiwan-based companies that purchased and then exported from the US "machinery used to fabricate metals and other materials with a high degree of precision", it said.

The father is now pending extradition to the US, while his son has been placed under home arrest in the US, where he is a legal resident.

North Korea has been subject to international criticism and sanctions over its nuclear and weaponry programs.