More than two dozen Irish nationals, including minors, will be deported after scamming Perth homeowners for renovation work that wasn't completed.

Police took action after the West Australian government’s consumer protection unit received 39 reports of teams of two to four men with Irish accents making unsolicited door-to-door approaches, persuading homeowners to carry out roof and other repairs.

One elderly person paid $17,000 for his driveway and home to be painted, but they only painted his driveway, failing to return for the remaining work.

An 82-year-old homeowner paid $1800 for roof painting, but only minor work was carried out and the resident was accompanied to the bank to withdraw the cash.

After an investigation, police searched a Hazelmere caravan park, taking five men and two 17-year-old boys into custody.

Items seized included more than $120,000 in cash and two Rolex watches valued at $36,000.

A further 19 women and children were then detained by the Department of Immigration and Border Protection.

All 26 have had their visas cancelled and they have been remanded pending deportation to Ireland.