Police arrested the 33-year-old on Thursday evening after two women reported him doing an indecent act.

A man has been charged after he allegedly rode a mountain bike pantless around a West Auckland cycleway.

The 33-year-old is facing multiple charges of doing indecent acts in a public place and will appear in the Waitakere District Court on Tuesday.

Detective Senior Sergeant Roger Small said police had received "a number of reports" of a man approaching female walkers near the Henderson Creek cycleway.

"The man had then been described as having exposed himself and on several occasions had committed an indecent act."

On Thursday evening, two women reported they were walking along the cycleway when a man rode past, pantless, on a mountain bike.

He allegedly stopped at a park bench and performed an indecent act as the women walked past.

The man was arrested shortly afterwards, Small said.

"We know the community will be reassured that this man has been caught. It's very frightening for anyone who is confronted with a situation like this."

Small encouraged anyone who had experienced a similar situation to report it to police.