Nineteen financial firms that conned more than 1,500 people out of £24 million through carbon credit scams "preyed on older people", the industry regulator said.
The companies offered "worthless" carbon credits - or Certified Emission Reductions (CERs) - and used high-pressure sales techniques on customers mostly ranging between 50 and 85-years-old, according to the Insolvency Service.
Those firms have been wound up by the service in the last 15 months, Consumer Minister Jo Swinson announced.
She said: "This is a particularly contemptible scam as it not only preyed on older people trying to maximise their savings, but also targeted their sincere desire to make ethical investments. Instead, investors have been left out of pocket with shares that are either worthless or do not exist.
Ms Swinson added that "robust action" would be taken against any more companies attempting the scam.
Employers who cheat their staff out of minimum wage will face "tough action" and be made an example of, said Employment Relations Minister Jo Swinson.
Paying less than the minimum wage is illegal. If employers break this law they need to know that we will take tough action.
This is why I'm making changes so it is easier to name and shame employers who break the law. This gives a clear warning to rogue employers who ignore the rules that they will face reputational consequences as well as a fine if they don't pay the minimum wage.
One of the women who has accused former Liberal Democrat chief executive Lord Rennard of sexual impropriety has defended the equalities minister Jo Swinson, saying she "tried to raise the alarm" but was "blocked further up the pay scale."
Swinson was one of the senior Liberal Democrats who female staff members and activists went to with their concerns over the peer.
Alison Smith told ITV News that she thought Ms Swinson would probably be "vindicated" by the independently chaired investigation into the allegations.