Insider trading is illegally profiting on information that was given to you in trust, while naked short selling is short selling without a documented ability to deliver the stock.
As far as I can gather from english language articles, the regulator has banned short selling in response to an article alleging fraud at wirecard. Bloomberg describes this as "unprecedented".
https://www.bloomberg.com/news/articles/2019-02-18/bafin-ban...
'Al Alam Solutions, a Dubai-based payments processor with skeletal operations in the Emirate, is the largest of the three “partner” entities. Wirecard refers clients to Al Alam in return for a share of any processing fees as commission. A former Al Alam employee said the business had six or seven staff in total and “the boss” was Oliver Bellenhaus, a Wirecard executive. The other partners are PayEasy Solutions, a Philippine payments group that shares an office with a Manila bus company, and Singapore-based Senjo. '
https://www.ft.com/content/a7b43142-6675-11e9-9adc-98bf1d35a...