Nicolas Pineault, 4, has been missing since Wednesday afternoon. (CBC)

Quebec provincial police in helicopters are again combing the area around the Nicolet River in St-Clotilde-de-Horton, where four-year-old Nicolas Pineault went missing last Wednesday.

Helicopters had searched the location around the central Quebec village last Wednesday and Thursday.

Police divers explored the river itself on Friday but have been unable to continue working in the water because of strong currents and poor visibility.

Despite the poor weather, police are doing their best to find the boy, said police spokesman Sgt. Gregory Gomez Del Prado.

"We haven't stopped our efforts, we've been investigating, gathering information," said Gomez Del Prado. "Every lead we had, we went into and double checked.

"We assess every day the need for teams — either in the helicopter, on foot or in the water."

The boy was last seen playing by the river outside his house when his mother, Chantal Jobin, who was watching him, had to step inside for a moment.

A black tuque belonging to the boy was found Friday afternoon in the river, four kilometres downstream from his home.

Nicolas was wearing the tuque, a black fleece coat and green pants when he went missing.

Police are still asking the public to come forward with any information relevant to the case.