Why did ex-diplomat & Hardeep Puri's wife Lakshmi sue TMC's Saket?

Ex-diplomat at United Nations Lakshmi Puri, who's Minister Hardeep Puri's wife, had sued TMC MP Saket Gokhale for defamation in 2021. This came as Saket tweeted that Lakshmi bought a property in Switzerland disproportionate to income. Calling for ED inquiry, he claimed Lakshmi's income could've only been ₹10-12 lakh. Later, Lakshmi said she earned $200,000/year when she bought the apartment.