The register
The register lists Sirius Remediation Ltd in Leeds as a licensed sponsor on Skilled Worker, an entry that goes back to at least 2026. Its rating on the register is Worker (A rating).
At Companies House the business is Sirius Remediation Limited (company number 04860112), a private limited company incorporated in 2003, 23 years ago. The registered office is at Russel House Mill Road, Langley Moor, Durham, DH7 8HJ, DH7 8HJ. By its SIC codes the business is in energy, water and waste.
A licence says an organisation may sponsor; it does not say it is hiring today. The way to find out is the same as for any employer: the careers page, the job boards, and a direct approach with a UK-style CV that says early that sponsorship would be needed.