Matthias Ungemach once went stroke-for-stroke against the legendary Australian "Oarsome Foursome" crew, but on Thursday he faced Manly Local Court over the fatal incident earlier in the year.

Ungemach, 52, was arrested at his Curl Curl home on Thursday morning after a nearly five-month investigation by NSW Police.

Antonio 'Tony' Plati, 66, died after he was struck while on an early morning walk at Freshwater on February 22.

The 66-year-old was found conscious in the middle of Oliver Street with serious head injuries and taken to Royal North Shore Hospital, where he later died.

Police launched a public appeal for information and formed Strike Force Clarefield to investigate the incident.

It will be alleged Ungemach failed to stop after his car struck Mr Plati.

He has been charged with dangerous driving occasioning death, failing to stop and assist after vehicle impact causing death and negligent driving occasioning death.

Police earlier this year raided Mosman Rowing Club, where Ungemach works as the director of rowing, and seized a VW 4WD and boat trailer.

Ungemach was granted conditional bail and will appear in court again on September 2.

Ungemach was a two-time world champion with the German team during the 1990s.

He was a part of the German men's coxed four team which won the 1991 world title in Vienna, Austria with a world record time of 5:58.96 - a mark which still stands.

He is also a two-time Olympian and was a member of the German team which finished fourth in the men's coxless fours final in 1992 in Spain.

The event was won by the Australian team of Andrew Cooper, Nick Green, Mike McKay and James Tomkins - commonly referred to as the "Oarsome Foursome".

Australian Associated Press