My 2009 (2010my) 3.6 has recently started to sound the seatbelt warning bong and light when you drop a front seat passenger off. It also seems to have become more sensitive to an item on the seat and the warning will sound even if something light is on the seat.

I’ve tried searching for an answer but no luck so would be grateful for advice

Sure there's a way to disable the bonging by a certain number of seatbelt buckle insertions into its hole. Read about it ages ago in here.

Yep, Ignition on, engine not running, doors closed. Sit in and insert drivers seat belt in and out 10 or so times until you get a bong.
Job done. To reverse it is the same procedure.  2007 Vogue TDV8 in Zermatt Silver with Charcoal

That’s great thank you.

Just to clarify Grofus, it’s the drivers seat belt to do that with? Does that switch the sensor off for both seats (don’t think the rears have them?)

Yes. drivers seat. Doesn't turn off the sensors but stops the noise. 2007 Vogue TDV8 in Zermatt Silver with Charcoal

Great, thanks Grofus, will give it a go

Nice one.... a simple solution to an annoying issue sorted while sitting waiting for the wife.....though she is the root of the problem. Series 2a LWB Hardtop - ex British Aerospace that was then used in an armed robbery! not by me!
2 door V8 1979 Range Rover
A slight Subaru blip..
110 County 200tdi
R reg 300 tdi Discovery Aviemore - gone to a local enthusiast to be resurrected in Transylvania
2003 TD5 Discovery2 - now sold
and the 2 wheeled Range Rover - BMW R 1150GSA

and finally the big lady of my dreams... 2012 Westminster - gives me a smile every morning

Thanks again Grofus, mission accomplished 👍

 2007 Vogue TDV8 in Zermatt Silver with Charcoal