Both incidents were captured via the GPS safety system fitted to all rally cars in the ERC.
Lukyanuk's Citroen C3 R5 was found doing 124.9km/h (78mph) in a 50km/h (31mph) zone. Not long after, in a 90km/h (55mph) zone, his speed had risen as high at 168.5km/h (105mph).
The Russian was fined €5000 (approximately £4400) by the clerk of the course on the Latvian event, but the event stewards then took further action.
The stewards' decision stated: "Obligation for the driver to accomplish for 10 days some work of public interest related to road safety, to be defined by the FIA Administration."
In addition to that, Lukyanuk will lose the ERC points he gained for finishing second in Liepaja if he finds himself before the stewards for a similar offence on public roads again for the remainder of the season.
An explanation from Lukyanuk, which was included in the stewards' report, read: "We had a problem with the brakes and had to fix it. The time for the road section was very short and we had to overspeed in order to be in time at the next TC [time control].
"We were almost alone on the road, there was not so much traffic. We are very sorry about our behaviour; it was bad for sportsmen."
Ahead of the Liepaja event, which was won by Oliver Solberg, Lukyanuk's start to the season had been a difficult one.
He destroyed his car on the Azores, before inflicting more damage at the next round in the Canary Islands.
Lukyanuk sits third in the ERC standings, 27 points behind series leader Lukasz Habaj.
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