NASCAR has confirmed that two Cup Series cars have been seized for further inspection at their R&D Center following Sunday's Pennzoil 400 at Las Vegas Motor Speedway.

Joe Gibbs Racing star Denny Hamlin's victory was made official when it was announced that there had been no issues in post-race inspection on Sunday evening.

However, when that statement was delivered, NASCAR also confirmed that the No. 20 driven by his teammate, Christopher Bell, was set for further scrutiny, along with the No. 43 Legacy Motor Club Toyota driven by Erik Jones.

Bell qualified on pole for Sunday's race and won the first stage in Nevada, eventually finishing in fourth position and adding a load of points to his tally.

Jones, meanwhile, finished the race in 20th, beating Legacy Motor Club teammate John Hunter Nemechek by one spot.

READ MORE: NASCAR star Denny Hamlin confirms Cup Series retirement goal at Las Vegas

Why does NASCAR inspect cars further?

What does this mean for those cars exactly? Well, cars are taken back to the R&D center from time to time, and often, it is just routine. However, if something illegal or that violated a rule were to be found during the added inspection, there would naturally be consequences.

This happened when Hendrick Motorsports' No. 17 Chevrolet, driven by Chase Elliott in the O'Reilly Auto Parts Series last season, was seized post-race at Pocono.

When inspecting the car at their R&D Center, NASCAR uncovered that the team's vehicle violated Section 14.3.3.2.1.1 K&L (Main Frame Rail Conical Receivers) of the NASCAR Rule Book.

As a result, hefty penalties followed: crew chief Adam Wall was suspended for three races, the team was fined $40,000, and the team was docked 40 owner points and 10 playoff points.

However, for the most part, the further inspections are for educational purposes, as outlined on NASCAR's official website: "Sometimes, NASCAR will choose cars to take back to the R&D Center, but that’s more for engine education than anything else."

READ MORE: NASCAR hits multiple Cup teams with penalties at Las Vegas including Team Penske