A Colorado man whose son was accused in a New York terror plot pleaded not guilty to charges of obstructing justice during his Brooklyn arraignment Tuesday.

Mohammed Wali Zazi, above, is accused of conspiring to destroy and conceal from federal investigators chemicals, glasses and masks related to a homemade bombing plot for which his son has been arrested.

In Denver, Zazi was previously charged with lying to federal agents, but that charge was later dropped.

Zazi is being held on a permanent order of detention, without bail.

His son, Najibullah Zazi, seen right, was charged in September with plotting to attack New York targets with homemade bombs. He pleaded not guilty to a charge of conspiring to use weapons of mass destruction and is being held without bond in the city.

Authorities said three other people traveled from the city to Denver over the summer and used stolen credit cards to help Najibullah Zazi buy ingredients normally used in homemade bombs.