Designed by architect William White - built in 1851 but the history goes way back !

The Old Rectory at St Columb Major, Cornwall is a major work by the architect William White. Commissioned by Dr Samuel Walker, Rector of St Columb, following speculation that the proposed Cornish bishopric would be based at St Columb. It was built in 1851, on the site of a 14th century moated medieval house. It is an asymmetrical plan rectory in a 14th century picturesque Gothic style.

Records of the original rectory go back 1309 when it withstood a siege by a mob of tinners It was probably built by Ralph de Arundell, rector from 1303 to 1329, a relative of the powerful Arundells of Lanherne.
The original medieval building was replaced in the 19th century, but traces of the moat remain. The enclosing an area 40m square.

The old parsonage house was built and moated round with rivers and fishponds in the second half of the 15th century by John Arundell. Salter thinks perhaps a tower like Gidleigh. Grade 2* C19 building on site.
Since this was a rectory tower it fits this sites definition of a pele tower, rather than a tower house, although it may have been quite sizeable. However, it may be possible the moat dated from the C15 and the nature of the early C14 house is unclear.

The bloke who owns the house is a bit of a nutter according to various news reports, Here's part of a article from the daily fail:

Brown retired at the age of 26 after making millions of pounds as a property developer, but his life spiralled downhill when he became addicted to cocaine.

The businessman took so much of the drug that his nose collapsed, and in 2012 he was sentenced to five years in prison for possession of class A drugs and a collection of handguns.

News report - https://www.walesonline.co.uk/news/wales-news/millionaire-property-dealer-jailed-five-2060418