AIKEN, S.C. (AP) _ The National Labor Relations Board has ordered a hearing to hear allegations that plastics plant officials had an employee arrested and put in a mental hospital to stop his union activity.

Gary McClain has sued his former employer, Tenneco Packaging, Aiken County Sheriff Howard Sellers and others, saying the company conspired with deputies to remove him from union activity.

The NLRB, in its order issued Monday, said there is reasonable cause to investigate McClain's allegations.

Although Tenneco was named in the order, the name of the company and its Beech Island plastics plant changed to Pactiv Corp. in November.

Pactiv has two weeks to answer the allegations, which will be heard by an administrative law judge this month or in early March, the NLRB said.

It only means ``there are disputed issues of fact in this matter,'' Pactiv spokesman Warren Hazelton said. ``We will cooperate fully with the board's order and anticipate a hearing in which the disputed facts will be addressed.''

McClain, who had worked at the plant for 17 years, said he was stopped by Aiken County sheriff's deputies on his way to work July 29 and arrested on a 4-year-old misdemeanor warrant.

He said he was taken to Aiken Regional Medical Centers and moved to Charter Rivers, a Columbia psychiatric hospital, where he was kept against his will for two weeks.

Sellers has supported his deputies' actions, saying he is confident the facts will come out in any court proceeding.

Organizers for the International Union of Operating Engineers said the ruling would strengthen their efforts at the plant.

Russell Britt, business manager of three operating engineers' union locals, said the ruling should be a boost to workers, many of whom he said were ``really scared after what happened to Gary McClain.''