Licensed private investigation firm serving Portsmouth and the entire NH seacoast. Former law enforcement with 34+ years experience. Court-admissible evidence. Free confidential consultation.

Serving Portsmouth and the seacoast: The NH seacoast is a densely populated corridor with Rockingham County Family Division, Portsmouth District Court, and significant cross-border activity with southern Maine. We serve the full seacoast region — Portsmouth, Dover, Durham, Hampton, Exeter, and all surrounding communities.

Private Investigation Services in Portsmouth, NH

Portsmouth’s affluent seacoast community, strong legal and business sector, and proximity to both Maine and Massachusetts make it a hub for a wide range of investigative needs. We serve private clients, attorneys, businesses, and insurers across the seacoast with the full suite of licensed investigative services.

Cheating Spouse Investigation

Discreet covert surveillance across the seacoast region and into southern Maine.

Surveillance Investigations

Workers’ comp fraud, insurance abuse, and corporate misconduct across the seacoast corridor.

Child Custody Documentation

Parental behavior documentation for Rockingham County Family Division proceedings.

Background Checks & Skip Tracing

Background investigations and people-locate services for Portsmouth and seacoast clients.

Corporate Investigations

Employee theft, workplace fraud, and due diligence for seacoast and defense-contractor businesses.

Litigation Support

Evidence collection and witness documentation for Rockingham County attorneys.

NH Seacoast Communities We Serve

From Portsmouth we cover the full NH seacoast corridor — Dover, Durham, Exeter, Hampton, Hampton Beach, Hampton Falls, Newington, Newmarket, Rye, Stratham, Greenland, Kittery ME, and the surrounding towns. Cases extending south into Massachusetts or north into Maine are handled with our statewide NH licensure and MA License #LP1599A for cross-border work.

Working With Rockingham County Attorneys

We support Portsmouth-area and Rockingham County attorneys with investigative documentation, witness location, and expert testimony. Our reports are formatted to NH evidentiary standards. We have experience appearing at Rockingham County Superior Court, Family Division, and District Court when testimony is needed.

Frequently Asked Questions

Is there a licensed PI in Portsmouth, NH?

Yes. Donahue Investigative Services (NH License #M-2025-0424) serves Portsmouth and the full NH seacoast. Mark J. Donahue is a former Salem, NH police officer with 34 years of law enforcement and federal task force experience. Call 603-785-2800 for a free confidential consultation.

What PI services are available in Portsmouth, NH?

Cheating spouse surveillance, child custody documentation for Rockingham County Family Division, workers’ comp fraud, background checks, skip tracing, corporate investigations, and litigation support for seacoast attorneys. All evidence is court-admissible.

Do you serve the entire NH seacoast from Portsmouth?

Yes. From Portsmouth we serve Dover, Durham, Exeter, Hampton, Newmarket, Rye, Stratham, Greenland, Newington, and surrounding seacoast communities. Cross-border cases into southern Maine and Massachusetts are handled with our dual-state licensure.

Free confidential consultation: 603-785-2800 — NH License #M-2025-0424 · MA License #LP1599A