A 22-year-old man has been arrested in connection with the disappearance of Samantha Murphy, 51, from Ballarat, Victoria.

Samantha Murphy went missing after a run in a regional park; her whereabouts remain unknown despite extensive searches.

Police suspect foul play and are investigating individuals with phone activity linked to the same tower as Murphy's during her disappearance.

The arrested man is currently cooperating with the investigation, but no formal charges have been announced.

Authorities are appealing to the public for any information and encourage contacting Crime Stoppers with tips.

Further updates on the case are anticipated.